I agree completely.
Dependence on works for salvation proves that we did not have faith that the sacrifice of Jesus was sufficient for our salvation. On the other hand, if we dont have the actions described, it proves that what faith we had wasnt real.
Again, I agree. Where I hae a problem with your post is that Devils and Demons encourage people to do good works. As Christ said, "A house divided against itself cannot stand" Matthew 12:25 when He Himself was accused of doing a good work (casting out demons) by the power of the devil. It can't happen that good works come from devils and demons. At the root of every good work is faith in Christ, trust in God, and desire to please Him.
So you would say then that Obamas wanting to feed the poor comes from his true and abiding faith in Jesus?